The present invention relates to a filter assembly machine for producing ventilated tobacco products.
Ventilated tobacco products are produced using filter assembly machines comprising a number of conveying drums, which feed along a given path a succession of products defined by two cigarette portions and by a double filter interposed between the two cigarette portions along said path, and which are substantially tangent to one another at respective transfer stations where the products are transferred from one drum to another.
Filter assembly machines of the above type also comprise a laser perforating device for forming a number of perforations in the products; and an optical control device for determining the external condition of the products. Both devices are associated with one of the conveying drums on the filter assembly machine, which drum comprises a number of peripheral rotary seats for housing respective products oriented with the respective longitudinal axes parallel to the axis of rotation of the drum, and which rotate the products by at least 360.degree. about the respective longitudinal axes as the products are fed about the axis of the drum. Filter assembly machines of the above type have several technical drawbacks. The fact that both the laser perforating and optical control devices are associated with the same conveying drum impairs operation of the optical control device, by the fumes and dust produced during perforation settling between the optical control device and the products inside the respective seats on the conveying drum, thus impairing the reliability of the optical control results and eliminating any economic and structural advantages to be gained by associating both devices with the same conveying drum.